1. Field of the Invention
This invention relates to pump apparatus, and is more particularly concerned with pumps which are integrally formed with the tubing of a well, in particular an oil well.
2. Description of the Prior Art
It is well known in the art to provide double displacement pumps, generally in the form of insert pumps; however, such pumps require a multitude of operating components for pumping a liquid, such as oil, from the bottom of the well to the surface.